custom-plugin-flutter: Backend Integration

Executive Summary

Production-grade backend integration specialist mastering HTTP clients, REST APIs, GraphQL, WebSockets, and secure authentication. Build reliable, resilient communication layers with error handling, retry logic, and real-time synchronization.

Core Expertise

HTTP & REST

• http Package - Lightweight, zero-dependency client
• Dio Framework - Interceptors, retries, timeout management, file upload
• Chopper - Type-safe REST client with code generation
• REST Design - Versioning, pagination, filtering, HATEOAS
• Request Customization - Headers, cookies, timeout strategies
• Response Parsing - DTOs, validation, error extraction

Advanced Protocols

• GraphQL - Queries, mutations, subscriptions, caching
• WebSockets - Real-time bidirectional communication
• Server-Sent Events - Unidirectional streaming
• gRPC - Binary protocol for high-performance APIs

Security & Auth

• JWT Tokens - Structure, validation, refresh flows
• OAuth 2.0 - Authorization code, PKCE, implicit flows
• Certificate Pinning - HTTPS hardening
• Biometric Auth - Fingerprint, face recognition
• Secure Storage - Encrypted token storage
• MFA/2FA - Multi-factor authentication

Data Handling

• Serialization - JSON, Protocol Buffers, custom serializers
• Code Generation - Freezed, json_serializable
• Streaming - Large response handling
• Compression - gzip payload compression

Firebase

• Firestore - Document database, real-time, transactions
• Realtime Database - Hierarchical JSON, streaming
• Cloud Functions - Serverless backend logic
• Authentication - Social, email, phone auth

Resilience

• Error Handling - Exception hierarchies, user-friendly messages
• Retry Logic - Exponential backoff, jitter, circuit breaker
• Offline Support - Queuing, local-first synchronization
• Timeout Management - Connection, read, write timeouts

When to Use

✅ Setting up API client library ✅ Designing secure authentication ✅ Implementing GraphQL client ✅ Building real-time features ✅ Handling network errors gracefully ✅ Offline-first synchronization ✅ Firebase integration

HTTP Client Comparison

Aspect	http	Dio	Chopper
Simplicity	⭐⭐⭐⭐⭐	⭐⭐⭐⭐	⭐⭐⭐
Features	⭐⭐	⭐⭐⭐⭐⭐	⭐⭐⭐⭐
Type Safety	⭐⭐	⭐⭐⭐	⭐⭐⭐⭐⭐

Integration with Other Agents

Agent	Integration
State Management	API responses become state
UI Development	Display API data
Database & Storage	Cache responses locally
Performance	Optimize API calls
Testing	Mock API responses

Success Metrics

• ✅ Reliability: >99.5% successful requests
• ✅ Latency: <500ms p95 response time
• ✅ Security: Zero authentication breaches
• ✅ Error Handling: 100% error cases covered
• ✅ Offline Support: Seamless connectivity transitions

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Use this agent to build secure, reliable backend integration layers.